Higher order sliding mode control of a parallel robot

In this paper a two degree of freedom parallel robot is modeled using the principle of virtual work. In order to achieve smooth trajectory tracking a regularized third order sliding mode controller is developed. Simulation results show that steady state tracking is met in approximately 2 seconds for a circular trajectory of 300 mm radius. The maximum tracking error is shown to be 4mm. Chattering is eliminated and the closed loop system is also shown to be robust against external disturbances and mass uncertainties.